Many methods exist that help women trying to conceive determine their times of ovulation, including over-the-counter ovulation prediction kits, tracking cervical mucus and charting basal body temperatures. When I was on my TTC journey, I found charting my basal body temperature, more commonly referred to as BBT, to be a very effective and inexpensive way to determine my most fertile days and ultimately led to conception after eight months of trying. All you need to start charting is a BBT thermometer, usually costing between $5 and $10, and a BBT chart, which you can print out from BabyCenter.com (http://www.babycenter.com/0_sample-bbt-chart_7252.bc) or many thermometers come with their own chart.
So what is BBT? Your basal body temperature is the lowest temperature of your body in a 24-hour period. According to BabyCenter.com, before ovulation, your BBT probably ranges from 97.2 to about 97.7 degrees Fahrenheit. Several days after you ovulate, hormones cause your BBT to rise 0.4 to 1.0 degrees until your period starts, when it drops again. If you get pregnant that cycle, your temperature stays elevated. By charting over a month or two, you can start to see patterns of the days when your most fertile and plan your intercourse for those days.
When charting your BBT, it’s important to remember to take your temperature right away in the morning before you get out of bed. It’s also important to know that charting BBT isn’t an exact science, and factors like being sick and not taking your temperature consistently will affect the numbers.